Currently, GOA (Gate on array) drive technology has been widely applied in the drive of a display panel. A GOA drive circuit is used for successively outputting line scanning signals to respective pixel unit lines. When the display panel is driven, a forward scanning approach, which is from a first line of pixel units to a last line of pixel units, can be adopted, or a backward scanning approach, which is from the last line of pixel units to the first line of pixel units, can be adopted. Generally, in the GOA drive circuit, a bidirectional selection unit is arranged to transmit a selection signal for controlling a scanning direction.
Usually, the GOA drive circuit is constituted by TFT devices. In a working procedure of the GOA drive circuit, a part of the TFT devices are always in an active state. That is to say, as for a P-type TFT, a low level signal is applied to its gate constantly; while as for an N-type TFT, a high level signal is applied to its gate constantly. When the TFT devices are in the active state for a long duration, they will be affected by a stress constantly. Under the influence of such stress, the electronic mobility of the TFT devices will change, so as to deviate a threshold voltage of the TFT devices, leading to the efficacy loss of the TFT devices. For example, with respect to the bidirectional selection unit in the GOA drive circuit, the TFT devices, which constitute the bidirectional selection unit, are always required to keep in the active state in the line scanning procedure, and thus in a high risk of efficacy loss. This will severely influence the reliability of the GOA drive circuit.